The left has been trying for 15 years to get this done through the courts, understanding that it will never happen if left to the people and unlikely if left to their elected representatives. So, its not surprising that some judge has finally issued an injunction, in fact Im surprised that it took so long.
Heres a case in which I was personally involved. I was the President of the Board of Inquiry in the case of an Army Major being discharged for homosexual activity. Her ex-lover was upset over who got the dog and took a stack of love letters into the CID office. She came into the board hearing and stipulated that she had engaged in homosexual acts. The reason that she and her lawyer did this was so that they could get to the Federal District Court in order to try to get Dont Ask Dont Tell overturned. They failed and you can read the opinion of the 10th Circuit of Appeals here:
http://ftp.resource.org/courts.gov/c/F3/52/52.F3d.851.93-3377.html
Would not be surprised to see this overturned if appealed but it may not be. Even if it is I believe DADT is going to go fairly soon one way or the other.
To me it's just unbelievable that the leftists are prevailing on this.